I eat, I breathe, I move so much
I leave you tender to the touch.
Within me lies help or harm for you
But one rarely predicts what I will do.
I move around, yet have no legs
and multiply, but lay no eggs.
My colors change as I get intense
But I keep no form, in my defense.

What am I?

Hint

I am neither solid nor liquid. Look to the sun for an example of my power.Hide